The recovery of fluid from an underground borehole can be accomplished by means of artificial lift whereby energy is supplied to downhole equipment and fluid is subsequently lifted to the surface. One type of artificial lift is the reciprocating of a downhole positive displacement pump by means of a reciprocating rod string which is attached to a source of reciprocating power on the surface of the ground above the borehole. Many oil and gas wells use this sort of artificial lift for the economic recovery of fluids from the wellbore.
The wellbore can also contain large amounts of gas, in addition to fluids, which reduce pumping efficiencies and make the task of subsurface pumping more difficult. The downhole pump is designed to pump an incompressible fluid. The presence of gas in large quantities can result in a gas lock condition within the downhole pump. In this condition the pump reciprocation results only in gas expansion and compression, alternately; with no net displacement of fluid and, therefore, no lift. This gas lock condition can exist for several minutes, hours, or even days until increased fluid head or some other factor causes the pump to be forced out of the gas lock and back into the essential fluid pumping operation.
Many gas lock breaking devices exist in the marketplace. However, a high degree of complexity and an inability to handle suspended solids, such as sand, iron sulfide, and scale, have limited the universal application of these devices. The present invention overcomes these limitations by the simplicity of no moving parts and the ability to operate in suspended solids, provided the rest of the pump assembly is designed to handle such solids. The unique way in which the traveling valve ball displacing tool realizes these achievements are the subject of the invention.